S7 Immobilizer Nightmare: Start-Up Issues Explained

I had a very similar issue with my 2015 S6 last summer. I have some basic experience working on cars but immobilizer systems are quite complex. The symptoms were identical, inconsistent starting and immediate stalling, along with the check engine light. Initially thought it was a fuel system problem, but the real culprit was an immobilizer fault due to incorrect key programming. Took it to a workshop where they ran full diagnostics on the ignition control system. Their scan revealed the immobilizer wasnt properly recognizing the key code. The fix required reprogramming the key to sync correctly with the immobilizer system. Total cost was 45 Euro for the key programming service. Before you head to a shop, could you share: Does the immobilizer light stay on after attempting to start? Have you had any recent work done involving the keys or remote start system? Are you using the original key or a replacement? What specific error codes are showing? This info would help determine if youre dealing with the same programming issue or potentially something different in the immobilizer system.

Thanks for the detailed response. After reading through the suggestions, I checked and the security light stays illuminated after failed start attempts. Running at 174726 KM and had recent service last month where they actually worked on the remote start system. Currently using the original key but had it duplicated about 6 months ago. The error codes point to the car electronics system, specifically P1832 and P1834. The key programming suggestion sounds promising since the timing matches with when I first noticed issues. Will try getting the key reprogrammed before exploring more complex immobilizer system repairs.

Thanks for the update. Those error codes (P1832/P1834) combined with the illuminated security light match exactly what I experienced. Based on the timing of your remote start work and key duplication, I'm even more convinced we had the same issue. In my case, the key signal interference started shortly after having similar work done. The immobilizer bypass wasnt necessary, it was just a programming conflict between the original and duplicate keys in the car electronics system. The fix involved: Clearing the stored key codes, Reprogramming both keys (original and duplicate), Resetting the immobilizer system, Testing the remote start functionality Total repair time was under an hour. Make sure to bring both keys when you go for the reprogramming. This allows proper synchronization and prevents future ignition control conflicts. If the programming reset doesnt solve it, then investigating deeper immobilizer system issues might be needed. But given your symptoms and recent service history, key programming should resolve the starting problems. Question, when you try to start, does the security light flash at all or just stay solid?

Thanks again for all the help. After checking today, the security light actually flashes 3 times before staying solid. This seems to further confirm your theory about the key programming being the likely cause. The symptoms align perfectly with what you described, especially the timing after the duplicate key and remote start work. Just booked an appointment to have both keys reprogrammed and the immobilizer system reset tomorrow. The shop quoted 60 Euro for the complete service which seems reasonable. Will make sure to bring both the original and duplicate keys to properly sync everything in the car electronics system. Really hoping this resolves the anti-theft system conflicts without needing more extensive repairs. Will update once I get the results from the key reprogramming service. Thanks for helping me avoid potentially unnecessary diagnostic costs by narrowing down the likely cause.